Upgrading my psu

Since my old psu can't handle the x1950xt I want, I need a new psu.

http://www.chieftec.eu/index.php?option=com_content&task=view&id=127&Itemid=

Should this psu be able to handle it and might it have any compatability issues with a 3 year old computer, which wasn't very high-end back then already?

But will there be any compatability issues with the computer (pins or something like that)?